Building material and process of making same



KIRSCHBRAUN 1,355,634 BUILDING MATERIAL AND PROCESS OF MAKING SAME Filed Ma-rch 2.' 1951 2 Sheets-Sheet 1 July 5, 1932.

VENTOR BY I I ATTORNEY July 5, 1932. L. KIRSCHBRAUN BUILDING MATERIAL AND PRoEss OF MAKING smE Filed March 2. 19:51 2 Sheets-Sheet 2 INVEVNTOR if:

hs'c'mzz ATTORNEY Patented July 5, 1932 UNITED STATES.

LESTER KIRSCEBRAUN, OF LEONIE, NEW JERSEY, .ASSIGNOR, ZBY MESNE ASSIGN- PATENT OFFICE MEETS, TO THE FLINTKOTE CORP RATION, OF BOS'IUN, SSAGHUBEITB, A 003-- POBLTION OF MASSACHUSETTS BUILDING HATEBIALAND PROCESS OF HAKINGEAKE Application filed. larch 2,

An object of the invention resides in the roduction of building material having a surace coating on one or both faces thereof possessing weathering properties far superior to those attainable with asphalt coating now commonly inc-.use in the commercial production of composite roofing material.

Another object of the invention resides in the provision of-a coating layer on one or both faces of a suitable base material which by 1Q virtue of its own peculiar properties will impart tOrthG product a high degree of fireproofness.

Still another object of the invention resides in the provision of a product having one or both faces thereof coated withimaterial of a character such that it is capable of withstandin internal flow at high temperatures and ot er action of,the weather which are destructive of asphalt coatings as now commonly used.

In the asphalt roofing industry at the present time large quantities of products are made in a wide variety of forms and shapes in which a base of felted fibrous material weather upon coatings of this kind is well known.' The destruction of, this coating material is apparently due to polymerization induced by the suns rays, causing a hardening of the outermost surface of the coating. Under the action of elevated temperatures,

this hardened or b'rittle outer surface tends to undergo a form of minute flow as a result of the internal flow and contraction of the hardened outer layer over the as yet unpolymerized portion, which brings fresh material to the surface. The cumulative ef- 'fcct of this action causes numerous cracks and checks to form in the surface layer into which. cracks the softer and still unaffected '*portions flow and themselves aiit light, and the specimen is 1931. Serial rename.

become -subject to the polymerizing action. Tghe net result is that in time, the entire coating becomes badly checked-and cracked throughout its depth. These cracks and checks permit ready access of water. and moisture to the base material and cause deterioration thereof.

The invention, in one of its forms is adapt- .ed to the manufacture of roofing as well as siding, sheathing and other building material havin as its base a foundation of felted fibres suc as rag, vegetable, asbestos and similar fibres formed into a web onany standard felt making machine. It is to be understood, however, that the invention is not re-v stricted to use in connection with a base comprising a felted'fibrous foundation but is a plicable to products in which the base may e of wood, asbestos cement com sitions, and

other well known base materia s suitable for roofing and other building purposes.

Briefly stated, the invention consists in the i use of a dispersion of waterproofingmaterial, such as asphalt, in water, for coating the surface-or surfaces of any desired type of base material to be employed for the purpose indicated. The dispersion in accord-' ance with the invention is one which is made in such a way and with essentially inorganic or mineral dispersing agent of such a character that when the water content has evaporated and the dispersed particles have coalesced, will produce a resultant film in which the material employed as'the dis- .Eersing agJent occurs .in the form of a gel or oneycom structure of such a nature as will impart mechanical stability or staticity to the dried film. Y

The suitability of aq ueous dispersions" of bitumen foraccomplishm the ob ects of the invention may be observe. and recognized by a microscopic examination,

according to the following technic: A-ve thin film of the dis rsion ispainted v a microscope slid: the film being suficientlz 'tliin to transhen allowed to dry thoroughly; the dried specimen is then washed with benzol or other bituminous solvent for leaching away the bitumen by placing the slide in an inclined position and to flow or run over and away from the dried specimen, the operation being thus continued until all the bitumen is leached out as evidenced by the disap earance of the black or dark color thereo the solvent is then allowed to evaporate completely from the specimen; upon microscopic examination of the residual material of the specimen, one should observe a honeycomb or cellular structure with the shape of the individual cells resembling rather closely the shape or configuration of the bituminous partlcles orlginally contained in the aqueous disperslon. Aqueous dispersions, the dried films of which possess adequate mechanical stability for accomplishing the principal object of the invention respond to the foregoing test by leaving a residual structure'as described, whereas in the case of those which are generally not suitable, no residue is left after the treatment described.

An aqueous dispersion offor example, to F. meltin point steam reduced asphalt is preferab y employed and mayglie made in accordance with Patent No. 1,

437, granted to me November 5th, 1922;.-

More particularly the dispersion is' preferably, in accordance with the invention, one which is made with material suchas bentonite as the dispersing agent. A characteristic and noteworthy property of a dis ersion of this character is the infusibility o the dried film 'ofthe'dispersion. ,That is to say, the dried film under the action of high heat as for instance the heat of a direct flame or other action, will ash itself in place without exhibiting any movement relative to the base. The importance of this property of the coating material from the point of view of fire protection afforded thereby, will at once be apparent to those skilled in the art. If the heat that may thus develop is as high or even higher than the melting point of the asphalt, the mechanical stability of the film and its resistance to flow will prevent the coating from flowing and even if the heat is sufliciently high to cause the asphalt to ignite, the asphalt will form into a carbonized crust and ash itself in place. I have further discovered that a coating material in the form of a dispersion as indicated exhibits greater and more firm retention of surfacing material such as crushed mineral grit, than do the ordinary coatings of asphalt in molten condition.

The film of wet dispersion coating ofl'er no resistance or impediment to the reception of 'orimpingement by granular surfacing material, which thus becomes readily part'ially'submerged in the coating layer and surrounded and wetted on the lower portions thereof with the coating material. Then as the water of the dispersion --is evaporated through the interstices between adjacent granules and the thickness of the coating layer becomes correspondingly decreased there is left upon these portions of the granules a film of asphalt extending outwardly of the general plane of the dried coating layer to a height corresponding to the original thickness of the wet dispersion coating layer in which the granules were imbedded, thus firmly anchoring the granules in the coating layer. These anchoring films which partially envelope the granules or surfacin material are similar to the setting of a nger ring.

Furthermore due to the better wetting of the surfacing material by the coating, the latter exhibits no tendency to blistering such as frequently occurs with the usual coatings of molten asphalt.

This bonding of the surfacing material to the coating layer is further augmented by virtue of the more adhesive nature of the steam reduced asphalt that may be employed in the form of an aqueous dispersion in accordance herewith. These properties of the dispersion coatings, together with the mechanical stability of the dried film thereof, as above pointed out, offer the advantage that comparatively thinner final films of coating material may be employed with far better resistance to weathering'action, and greater relative or comparative quantities of mineral surfacing may be forced into or embedded in the coating layer. i

' Thus, where a dispersion of the character herein described is applied at such a rate as to leave a dried coating film of such thickness that say sixteen pounds of asphalt cover one hundred square feet of surface, crushed slate to the amount of sixty pounds per one huneral surfaced material in which molten asphalt is employed as the coating material,

where under normal conditions the ratio of surfacing to coating per unit generally is about one to one, and even under extraordinary conditions of applying the surfacing, as e. g. using heated slate and severe pressure for embedding the same, this ratio-does not exceed two to one.

Another important feature of the'inventi on which results from the use of aqueous dispersions as coating material is the ease with which mineral or inorganic fillers may be incorporated in the coatin material to provide bulking and/or weig ting' effects such as may be obtained-by the use of slate dust,

ICC

finely ground diatolnaceous earth, or the like.

' Mineral fillers 'as- Well as certain water soluble, fireproofing salts may readily be incor orated in the coating material to a con- .tro lable and greater extent than is possible with molten asphalt.

In'adapting the invention .in practice to the production of roofing 0r sidlng materlal u v u Furthermore, in order torealize the advantages of the invention as heretofore described, it is desirable that the size of the comminuted surfacing material be regulated in accordance with the thickness of the dis persion layer in order to avoid, during the subsequent processing, ek'udatio'n of the wet dispersion seating upwardly through the In the figures, the reference character S represents a sheet of felted fibrous material, which may be a sheet of ordinary roofin felt made of ra wool, hair, asbestos or like fi bres, as delivere from a supply roll 10. The sheet may be'impregnated with a water-resistant saturant such as asphalt of 80 to 160 F. melting 'point, as by leading the sheet over a series of rolls 11 into a bath of the saturant contained in the tank 12. The impregnated sheet emerging from the tank passes between a pair of squeeze rolls 13 for substantially completely removing excess 'saturant from the surfaces thereof. After the sheet leaves the saturating tank, it is preferably allowed to form a loop or festoon 15, in order to provide a loose length of material to assist in guiding the sheet properly to and past the coating station.

The sheet then is conducted over a supporting and guide table 16a .and beneath a feed pipe or other suitable feed device 16. through which an aqueous dispersion of asphalt of the character hereinbefore indicated, is applied to the upper surface of the sheet. The layer of coating material thus deposited is then caused to be distributed evenly over the sheet by a doctor roll 17 which preferably is in the form of a hollow, slowly rotatable roll mounted on a support (not shown) so as to be adjustable toward and away from the surface of the coated sheet, this roll being arranged and operated so as to brush out and distribute any lumps of the coating material rearwardly thereof. and to provide for the production of a smooth and uniform coating layer.

The sheet carrying the smooth film of dispersion coating on its upper surface then passes beneath a hopper or other feed device 18 containing a supply of comminuted surfacing material such as crushed mineral grit which is showered upon the coated sheet in any approved fashion, whereupon the sheet may be conducted into an enclosed chamber 20 through a narrow elongated slit in the end wall thereof. The chamber 20 is preferably divided by a plurality of horizontal partitions 21 into a plurality of compartments 22, 22a and 226, through which the sheet may be threaded and progressively fed. Endless conveyor belts 23, 23a, 23b, 23c and 23d, preferably in the form of foraminated belts or wire mesh screens are arranged as shown in the compartments of the chamber 20 in such position that the sheet travelling through these compartments will be supported thereby and prevented from saggingduring its travel therethrough, these belts being ,preferably driven at a speed equal to the speed of travel of the sheet. The belt 23a, preferably extends exteriorly of theforward wall of the chamber 20 for a purpose as will presently appear. The sheet is fed out of the lowermost one of the compartments through a narrow slit in the forward end wall of the chamber 20 and is reversed around a roll 25 and then passes in an opposite direction through the compartment 22a supported by the belt 23a. Where it is desired that both faces of the sheet be coated, the coating material for the reverse face of the sheet may be supplied as by means'of a feed device 27 similar to that shown at 16 and arranged between the forward end of the chamber 20 and the reversing roll 25. The coating material applied to the reverse face of the sheet may be regulated as to thickness and smoothness as by means of an adjustable doctor roll 28 constructed and operatingsimilarly to the doctor roll 17, the forward end of the belt 23a serving as a bed support at this point. Thereupon suitable surfacing material may be supplied to the coated reverse face of the sheet, as by means of a hopper 29,'preferably before the sheetenters the compartment 22a. The sheet then travels through the compartment 22a and emerges at the opposite end, where it is again reversed around a roll 30 and enters the compartment 226 through another slit in the rear wall ofthe chamber 20. The sheet may then'travel through the compartme'nt 22b in any number of successive passesdesired over the supporting belts arranged therein. By regulating the size of the particles of surfacing material in relation to the thickness of the coating as hereinabove described, the sheet is enabled to pass around the reversing rolls 25 and 30 without giving rise to exudation qf wet coating through the layer of. surfacing,material and into contact with the surface of the roll, surplus surfacing material being recovered in receiving hoppers 32 and 33 mounted adjacent the rolls 25, 30 respectively, and reclaimed for reuse if desired.

Provision is made for partial elimination of 'water from the coating layer or layers during the passage of the sheet through the chamber 20. For this. purpose,-one wall of the uppermost compartment in the chamber 20 is connected to a conduit 34 for introducing a current of hot or warm air and by means of connections 35, 36, the hot air thus introduced may becaused to traverse the lower compartments seriatum in countercurrent heat exchange relationship with the coated sheet, the exhaust air and moisture withdrawn from the sheet being discharged through an outlet pipe 37 connected to one wall of the lowermost compartment 22. The air fed to' the chamber is preferably at a temperature of 250 F. or thereabouts.

'After the sheet leaves-\the chamber 20 it is then subjected to conditions for completing the drying of the coating layer or layers. For this purpose, the sheet is led through a drying chamber 40 by feeding the sheet over a guide roll 41 and through a narrow elongated slit preferably'in the top wall of the chamsired interval.

ber. ln'order to conserve space and to provide ample time for the complete dryin of the sheet, the sheet is fed through the rying chamber in the form of loops or testoons.

It is essential, however, that the mechanism for forming the successive festoons be such as to avoid undue pressure upon the sheet, because of the soft condition of the coating layer. Accordingly, the drying chamber has mounted therein a festooning mechanism known as a stick looper,'inwhich loose c on the incline ot the conveyor 45, the sheet is caused to term into loops or festoons. When the to of the incline of'the conveyor is reache the sticks are successively delivered onto iestooning chains 47 moving in an endless path and the sheet is thus carried along horizontally in the form oil-loops, the relative speed of the conveyors 44,45, and 47 being regulated to form the loops at any de- As the sticks successively reach the forward end of the conveyor chain 47, the sheet is drawn from the loop or festoon and the sticks fall through the chute 49 to-be returned to the conveyor 44.

Within the drying chamber 40 are located steam coils or sections of pipes 50 for conveying a heating medium such as superheated steam therethrough in order to maintain a temperature within the chamber at approxi'- mately 250 'F. If desired this chamber may be heated by the introduction'thereinto of combustion gases from a directfiredoven or combustion chamber. A series of draft fans 52 are preferably connected to the sidewall of the chamber 40 for circulating the air.

within the chamber and exhausting the mois ture-laden- ,ai'r. "Advantageously, these fans may be connected to the top and bottom walls of the chamber, or arranged in upper and lower rowsso that the u per fansawill ex- .haust the vapor develope from the coating on the upwardl facing loops of the sheet and the lower ans will exhaust the vapor 1 developed from the coatingon theintervening downwardly facing loops thereof, as in:

' dicated by! the arrows.

. i has passed over thelast series of dryers 54, it

After t e sheet has thus been subjected to conditions for completely dryin'g'the coating layer, it is withdrawn from the chamber 40 throu h an elongated slitin the forward end wall 1; ereof "and led over a series of drums 54 through which a suitable cooling medium may be circulated for partially coolmg the sheet and causing the coating to set and harden, these drums servingalso liOPIOVldG-tltlfla tion for the. sheet and assisting in its removalfrom the drying chamber 40.- After the sheet may then be fed. over another loop forming or festooning mechanism,56 similarto theione located within the drying chamber 40. The

sheet'may thus be carried along and .subject- Y ed to cooling conditions for causing the coatmg layer to become completely set and hardened. The finished material delivered from the testooning mechanism 56 may then be led to any suitable winding mechanism or cutting mechanism, indicated conventionally at 60, tobe Wound upon mandrels and formed into roll roofing or building paper of desired-size and weight, or for severing the sheet into shingles, shingle strips, or units of any desired size and shape.

While I have described in considerable detail an arrangement for adapting the'invention to the manufacture of felt base material it should be understood that numerous modifications may be made in the arrangement described. Thus, for example, the sheet may be'coated with the dispersion and surfaced as described on one face thereof, and then immediately subjected to drying conditions such as in the chamber 40 for complete- 'ly drying the coatin layer,.whereupon the sheet may be reversed and coated with the dispersion on the reverse face, followed by the application of surfacing material there-' to before .or after being subjected again to drying cnnditions for completely drying the coating layer on the reverse face; finally passing the sheet ove cooling drums and/or through a cooling stgge as indicated at 56.

The invention a1 0 finds adaptation and aifords a marked advance in the production of building material in which the base is of wood. I have found in accordance with the present invention that the dispersion material asheretofore describedfwhen applied to a wooden base serves, in addition to a weather protection mediunrto impart to the Wood base a substantial degree of fireproof qualitiesby virtue of the infusibilityand static qualities of the resultant bituminous coating layer. The fireproofness of the base may be htill further increased by incorporation of soluble fireproofing salts such as ammonium 1 phosphate, in the dispersion, which will penetrate into the wood base when the aqueous dispersion is applied thereto, so that upon elimination of'tlie water, these salts will be present in the pores of the base and impart additional fireproofness thereto.

The dispersion coatings as herein" described, are likewise advantageous in the production of building materials in which the base is of metah'such as corrugated sheet.-'

iron. In such cases the dispersion coating matenal may serve a weatherprotective and rust inhibitive medium or it may-have incorizo 'porated therein rust inhibiting materials i such as soluble chromate salts, for thispurpose. r

Rigid materials ut asgasbestos cement compositions, although usually considered to be of fireproof nature, may nevertheless be improved in their weather and wear resist- .ing properties .byapplication thereto of the dis ersion coatings as herein described. In

. suc cases the dispersion coating may be apshin les are made by wet machine operation,

the ispersion coating and an overlaying layer of surfacing material may be applied to the formation stripped from the collecting cylinder or make-up roll of the fabricating machine, after partial .or complete elimination of water from the base sheet or slab, and after the dispersion layer has been dried to the desired extent, units of desired sizeand shapemay be cut in any convenient way from the slab. If desired, the coating material may .be applied as indicated to asbestos cement shingles after they have been formed of the desired sizeand shape in accordance with practice known in the asbestos. cement shingle art. Thus, the asbestos cementshi in a ath of, the dispersion coating material, the coating being applied in the desired thickness andthe coating step followed by a" surfacing o eration under conditions as herein descri In any event, the weather and wear resisting properties of the asbestos cementtype shingles may be'enhanced in ac- .cordance with the invention. ,Anadded advantage of'coating this type of shingle with dispersion coatings as herein described resides in the fact that mineral surfacing of various colors may be applied to produce cement type shingles in a variety of colors without necessitating the use of expensive pigments as is now required in the asbestos cement shifigle art..' The coating material as thus applied to asbestos cement shingles also' functions as'a cushion to prevent breakage of the shingles in the packages during handling and transport due to the normally I frggifie character of these shingles.

ile the obj cct andadvantages of the invention as heretofore described will be apreciated by. those skilled in the art, it may a e pointed out here that this invention comprises a radical departure in the roofing industry for the manufacture of composite roofing or like material, and also that other t pes of emulsions, the dried film's of which 0 not have the resistance to flow: or the mechanical stabilityand static properties of the dispersions employed inaccordance with my invention, as well as cut-backs'or similar compositions which require fibre to. reenforce the coating and to revent flow thereof, do not possess the weat 'ering ability and other advantages that accrue from the presles may 'be sprayed with, or immersedreenforce the film and revent flow, they exhibit a tendency to a sorb moisture as soon as the films surrounding the fibres have undergone the least Weathering action. The absorption of moisture by the fibres may then cause'the fibres to swell and induces cracking of the coating particularly under frost action and additionally the fibres, being of organic nature, are readily susceptible to decay, as a result of all of which, avenues for the entrance of moisture to the base are readily'rpresented.

I aving thus described my invention it will be apparent to those skilled in the art that numerous variations and changes may be made therein without departing from the spirit of the invention as set forth in the appended claims:

I claim as my ihvention:

1. The process which comprises coating a face of a foundation material with a layerof an aqueous dispersion of bitumen capable of forming, when dry, a film in which the dispersing agent is distributed in the form of a honeycomb structure, and thereafter deposit ing upon said layer a layer of comminuted surfacing material while the layer of dispersion coating material is wet and uncoalesced and in a condition such that the deposition of the comminuted surfacing material thereon will not interfere with the formation of the gel or honeycomb structure in the coating la er and subsequently removing the water rom the aqueous dispersion to thereby cause the bituminous particles to coalesce around the, comminuted surfacing material to anchor the same.

2.- The process which comprises continuously advancing a water-resistant sheet of felted fibrous material, applying a coating consisting of a dispersion of bitumen to a face of the advancing sheet, doctoring the coating to a predetermined thickness, showering the doctored coating While it is still Wet and uncoalesced with comminuted surfacing material of a grade of size in relation to the thickness of the doctored film such as to avoid exudation of coating material, and subjecting the sheet to drying conditions and completely drying the coating material for effecting coalescence of the dispersed particles 'thereof.

3. As an article of manufacture, building material comprising a base of felted fibrous material impregnated with a weather resistant. material and a coating therefor, said coating comprising a waterfree film of an aqueous dispersion of bitumen, the said film having the dispersing agent distributed therethrough in the form of a honeycomb structure, and a surfacing layer of comminuted mineral material adherent to and partially Embedded in said coating, individual particles of said surfacing material being coated with ent invention. Where fibres are employed to and anchored by coalesced films of said coatin g material extending outwardly of the general plane of outer surface of the coating layer on the base.

4. As an article of manufacture building material comprising a base and a coating therefor, said coating comprising a water-free film of an aqueous dispersion of bitumen, the said film having the dispersing agent distributed therethrough in the form of a honeycomb structure, and a surfacing layer of comminuted mineral material adherent to and partially embedded in said coating, .individual particles of said surfacing material being coated with films of said coating material extending outwardly of the general plane gfouter surface ofthe coating layer on the ase.

5. The process which comprises continuously advancing a water resistant sheet of felted fibrous material, applying a coating consisting of a dispersion of bitumen to a face of the advancing sheet, said dispersion being of a character such as to form, when dry,amechanically stable film, applying comminuted surfacing material over said coating layer while it is still wet and uncoalesced, the particles of the surfacing material being of such a grade of size in relation to the thickness of the wet dispersion layer as to permit subsequent handling of the sheet while the coating is still wet without exudation of the coating material through the interstices between the particles of surfacing material, and subjecting the surface sheet to drying conditions for completely drying the coaling layer and effecting the formation of a mechanically stable film and the coalescence of the dispersion around the embedded portions of the grit to secure the same to the film.

6. As an article of manufacture, building material comprising a base and a coating therefor, said coating comprising a water free film of an aqueous dispersion of bitumen, and a layer of surfacing material aflixed to said coating by coalesced films of the coating existing in a form resembling a finger ring settin partially surrounding the individual partic es of the surfacing material.

' 7. As an article of manufacture, building material comprising a base of felted fibrous material impregnated with awater resistant material and a coating therefor, said coating comprising a water free film of an aqueous dispersion of bitumen, the said film having a honeycomb structure to impart mechanical stability suflicient to enable the film to resist flow under-heat, and a layer of comminuted surfacing material affixed .to said coating layer by the coalescence of the dispersion.

Signed at Rutherford, in the county of flBergen and State of New Jersey, this 27th 'day of Febr'uary,'-A. D. 1931.

" LESTER KIRSCHBRAUN. 

